I have scoured the forms and found examples where a wet vent would be permissable here if my waste to the street is going the other direction, thereby wet venting the toilet and showers through the vanity. In my case the last fixture on the horizontal would be the back to back vanities, meaning it wouldn't really be a wet vent (except for the vertical section between the vanities and the horizontal). Is it permissable to vent the 2 showers and 2 toilets through the vanities as I've shown (as long as I'm within the 2 pipe diameters of fall and 60"). Or do I need to add a re-vent between the showers and toilets? And can I lay the wye-45 combos on their sides like that? I had thought they needed to be 45° from vertical or less, but as you can tell I'm a homeowner who's still learning. Appreciate any advice!
